[Effects of transcutaneous electrostimulation of auricular concha at different stimulating frequencies and duration on acute seizures in epilepsy rats].

Objective: To observe the inhibitory effect of auricular concha transcutaneous electrostimulation (ACTES) of different frequencies and duration on acute seizures in epilepsy rats so as to select a better stimulating parameter for relieving epilepsy.

Methods: According to the stimulation duration of ACTES, 44 Sprague-Dawley rats were randomized into: 30 s, 5 min, 10 min, and 30 min groups. Epilepsy model was duplicated by intraperitoneal injection of PTZ (pentylenetetrazol, 50 mg/kg). Cerebral field potentials delivered from the fixed 4 recording electrodes array (A-P: -3 -6, L: 4 - 6, H: 1. 5) and reference electrode (a fixed screw) touching the cerebral dura surface were recorded using a data acquisition system (Cerebus 5.0 system). Transcutaneous electrostimulation (1 mA, duration 500 micro(s)) of frequency 2 Hz, 20 Hz and 100 Hz was applied to auricular concha by using an electric stimulator. The anti-epileptic effects of ACTES were evaluated by using the duration and rate of seizure suppression.

Results: (1) The anti-epileptic effect of 20 Hz -ACTES was markedly longer than those of 2 Hz and 100 Hz in the duration of seizure suppression (P < 0.05). (2) After 2 Hz-ACTES, the anti-epileptic effects (duration and inhibitory rate) in 30 s-stimulation group were markedly longer than those of the 5 min-, 10 min- and 30 min-stimulation groups (P < 0.01, P < 0.05). (3) After 100 Hz-ACTES, the anti-epileptic effects (duration and rate of seizure suppression) in the 30 min-stimulation group were markedly longer than those in the 30 s-, 5 min- and 10 min-stimulation group (P < 0.01, P < 0.05).

Conclusion: ACTES at 20 Hz can effectively lessen epileptic seizures, and under fixed stimulating frequencies of 2 Hz and 100 Hz, the anti-epileptic effects of 30 s ACTES and 30 min-ACTES are obviously better in epilepsy rats.